Tractor-trailer coupling device



' Sept. 7, 1948. i 's.'R.s'rr\n1\DER` 2,448,744

TRACTOR-TRAILER COUPLING DEVICE Filed April 26, 1946 INVENToR. Y

I jpeg/cer HS l'rader Patented Sept. 7, y1948 y 1 UNITED STATES PATENT OFFICE i 2,448,744 l l TRACTOR-TRAILER CoUrLING DEVICE Spencer R. Strader, Hanford, Calif.l Application April 26, 194s, serial No. `565,679

7 Claims. 1

(Cl. ZBO-33.15)

My trailer hitch is provided with a clevis er a l pair of open jaws permitting different angular positions in all directions between tractor and trailer, 4without slack or rattling at any time. It is very easy to assemble and assures constant pull or tension between the assembled parts, which are yieldably connected.

The` following objects and advantages of the trailer hitch should be noted: Safety, quick and easy hitching up and equally quick unhitching; elimination of all slack and rattling; complete limbering or toggle action without slack between tractor and trailer.

With these features in view the invention will be readily understood from the following description with the aid of the attached drawings being part of the application.

'l In the same, like numerals refer to the same details in the different views.

` Figure lis a side elevational view in part section, of the assembled parts of the trailer hitch;

Figure 2 is a horizontal section of the drawbar, connecting the tractor with the trailer, taken on a plane along line 2-2 of Figure 1;

lFigure 3 is a vertical section on a plane along line 3-3 of Figure 1;

Figure 4is a vertical section taken along line '1 -4 of Figure l;

' Figure 5 is a top plan View of the upper jaw with the key-hole shaped opening for the hitch bolt;

Figure 6 is a similar view' of the bottom jaw ofthe clevis in part section;

Figure 7 is a fractional side view of a cam lever and sides. V

Numeral I is the tail end of the motor car o1' tractor'and'numeral II is the front end of the trailer frame.

The tractor frame Il) has a clevis I2 with a straight upper jaw portion I'3 directed parallel to the lower jaw portion I4, spaced above thelatter, thus providing open jaws.

The upper jaw portion I3 has a, bolt hole I5, whichflts a connecting or hitch bolt I6 with a slight play between them. However, the hole I is provided with a radially, rearwardly directed slot I8 for a key I1 on the hitch bolt I5.

For the purpose of hitching the trailer portion or tongue II to the clevis I2 on the tractor I 0, a drawbar I9, preferably made of flat band iron, is provide-d and securely bolted as at 20 on top ofthe front end II of the trailer, while the freeend of the drawbar I9 is releasably heldby the hitch bolt I6,

co y

" 5 the iside of'the hitchvbolt and thusl 'eliminates vThe lower J'aw I4 of the clevis I2 is xed securely on the top of the tail end I0 of the tractor by means of screw bolts 2|l 22 of which the head 22A of bolt 22 serves as `a pivot pin for the drawbar I9. y The forward end of this bar is for that purpose provided with a large hole 23, Figure 2, which engages not only the head 22a of screw bolt 22 butalso thevend of the connecting or hitch bolt I6. This hole 23 being widened rearwardly to permit free transverse displacement of said hitch bolt to give suificient free movement orftoggle action inv all directions between the tractor and the trailer.

The upper jaw portion I3 of the clevis I2, as already stated, has akeyholeshaped aperture I5 see Figure 3 with the side slot I8 for the upper part of the hitch bolt I6 and the bolt has a key I'I on the same side thereof as the lifting handle 24 at the top thereof. The key I 'I is shown nat and straight with an inward bevel at the bottom to facilitate entry, and above the same, at a distance slightly more than the thickness of the clevis jaw portion I3, a circular collar 25 is provided on the hitch bolt I6. In a sleeve 2B, secured on top of said collar, is furnished a latch pin 21, actuated by a spring 28, for axial displacement, so as to project below said collar Y25 and thus engage in the key slot I8 of the hole I5 when the hitch bolt I5 is turned into engaging position.

In yorder to unhitch the' trailer from the tractor, all that needs to be done is rst to lift the latch pin 21 out' of engagementwith the key slot I t. This now permits the turning of the handle 24 until the key I1 registers with the slot I8 whereupon the hitch bolt I6 can then be drawn out and the tractor and trailer II'I and II separated.

So far as the invention has now been described, there still exists a possibility of rattling between the parts, because of the considerable amount of play existing in the drawbar holel 23 around the pivot bolt 22 and the hitch bolt I 5 see Figure 2; and in order to overcome this rattling the following device is added.

This yielding device consists of a slide member3ll `placedflatly on top ofthe free end of the drawbar I9, so as to be slidable back and forth thereon and is providedv with an abutment lug 3| about midway thereof. A hood or housing 32 for said slide member 3D is provided on top of thefdrawbar I9 and integrally joined thereto as by welding.: This hood 32 isiopen `at both ends and contains a coiled compreSSOn Spring 33, which, with its forward end abuts against the lug 3|', while its rear end contacts with a cam member 34 and in' this manner the spring 33 urges the slide v3l) -constantly forwardly towards the hitch'bolt Ilil4 The slide member 3l) has for this purpose a concave front edge 35 .abutting against all loose play or rattling between the engaged parts.

The cam 34 forms a xture on a cam lever 36 which is pivoted to turn in the housing v32 as at 31 and is inserted therein through va horiaontal slot 38 in one side of the housing while held with the handle in a substantially horizontal position. When swung into vertical `position or to the rear the lever 36 is prevented by the cam 34 itself from being drawn out.

With the cam handle 36 pointing forward as in Figure 1, and the cam 34 abutting against the spring, the trailer hitch or coupling is in locked position with the tractor. By swinging the cam lever 36 tothe rear, the spring pressure against the slide 30 is released and accordingly the hold of bolt I6 bythe slide 3Il` ceases.

The bitching or coupling between the two vehicles takes place in the following manner.

The hitching Aparts Il] and lI I are iirst placed in correct, relative position vwith the end of lthe drawbar I9 resting on the lower jaw I4 and the bolt hole -23 engaging the -head of the pivot pin 22, while'at the same-time its rear portion is open for entering of the hitch bolt I 6 through the hole l5 in the upper and lower jaws I3, I4, care being taken that the bolt key I'I registers with the slot i8. Previous to entering bolt -Hi in the clevis I2, the clamp handle 36 is turned back, thus rotating the cam 34 to the rear inorder to release the spring pressure-on the slide 30, thus permitting the pushing ofslide 3l) out of the way of the hitch bolt-I 6,

In order `to complete the locking of the hitch bolt I6 in the clevis, its handle is next turned forward into lengthwise directi-on of the tractor. As a consequence, the key I1 turns sideways away from vthe slot I8 with its top face under the bottom face of the upper jaw I3, thus `preventing the jumping out ofthe hitch bolt. Simultaneously, the latch pin 2'! snaps into the said slot I8, thus preventing the hitch bolt I6 from turning, thereby making its locking complete.

With the parts in this locked position andthe clamp handle 36 to compress the spring to exert forward pressure .of the slide against the hitch bolt IE, all rattling is eliminated, whilestill per-,

mitting toggle action between tractor and trailer.

It is to be understood that the invention as herein disclosed is not limited to the description and details shown, but that the same may be varied in accordance with the scope of the subjoined claims.

I claim:

l. A trailer hitch or coupling comprising a rearwardly directed xed arm on a tractor vehicle and a forwardly directed arm on a trailer vehicle; a clevis member fixed on one .of said arms and having an upper .and lower jaw spaced apart, a hitch bolt adapted for entering axially aligned apertures in said jaws, a pivot pin fixed on the lower jaw, said other arm consisting of a drawbar being provided with a suitable opening for simultaneousengagement'with sai-d hitch bolt and said pivot pin, the rear edge of said'opening being covered on the radius from the axis of said pivot pin and means for taking up slack be-v tween said hitch bolt and'said-'arms 2. A trailer hitch or coupling'as 'described in claim l, said means consisting of a yieldable slide member on the other 'ofsaid 'arms adapted for constantly contactingwith theperipheral surface of said hitch bolt.

3. A trailer Vhitch or ycoupling as descrbedin claim 1, said means consisting of a yieldable slide member on the other of said arms provided with a concave surface shaped on the longer radius than that of the slide bolt, adapted for constantly contacting with the peripheral surface of said hitch bolt, a radial slot formed from the aperture in said upper jaw, a key on the side of the hitch bolt, a turning handle on the hitch bolt and a fixed collar below the handle at a distance above said key about equal to the thickness of the upper jaw; whereby upon insertion of the bolt through said jaw aperture and said key registering with said radial slot, the hitch bolt will be held from withdrawal after rotating the bolt until said key is out of registration with said slot.

i. The invention set forth in claim 1 wherein said means consists of a yieldable slide member on said drawbar adapted for constantly contacting with the peripheral surface of said hitch bolt, and a compression spring conned between xed points on said slide member and. said-,drawbar.

5. The invention set forth in claim 1 wherein said means consists of a yieldableslidemember on said drawbar adapted for constantly contacting with the peripheral surface of said hitch bolt, and a compression spring confinedbetween X-ed points on said slide member and said drawbar; a xed hood on the 'drawban forming a guide for said slide said compression spring acting between xed points on the .slide and `the hood.

6. The invention set forth in claim v1 wherein said means consists of a yieldable slide .member on said drawbar adapted for constantly contacting with the peripheral surface of saidrhitch bolt, and a compression spring confined between fixed points on said slide member and said drawbar; a fixed hood on the drawbar, forming a guide for said slide said compression spring weting between fixed points on theslide andthe hood; a cam lever turnable in vsaid hood adapted for increasing and Idecreasing the spring ,pressure.

7. A trailer hitch Ior coupling as describedin claim 1, said means consisting of a yieldablefsli'de member on the other of said arms adapted for constantly contacting with the peripheral surface of said hitch bolt, a radial slot ,formed from the aperture in said upper jaw, a key on .the side of the hitch bolt, a turning handle on the hitch bolt and a xed collar below the handle .at a. -distance above said key about equal to the thickness of the upper jaw; whereby upon .insertion of the bolt through said jaw aperture and said key registering with said radial slot, the hitch bolt will be held from withdrawal .after rotating the bolt until said key is `outof registration with said slot; a snap latch adapted forengaging in said slot when said key has been-turned away therefrom, thereby liatching the bolt in position and preventing tractor and trailer from unhitching.

SPENCER R. ISTRADER.

REFERENCES CITED The following references are of recordin the iile of this patent:

UNITED STATES PATENTS Number Name Date `385,868 McNab July.10,.1'888 2,140,132 

